225 4 Stroke Tell tale Flow weak

[Hedland1]

I took a 6.5 cc out with a 225 FET 4 stroke for a test drive today and the tell tale was quite weak at idle and when we took off it didn't get any stronger. The water coming out was quite hot. The owner said that its been like it since new (only 137 hrs) and was serviced at 80 hrs. I spoke to the mechanic and he assured me that this was the case with the newer technology. No fault alarms came up. The water temp cooled slightly when motoring along but at idle became very hot coming out. Just want to know if this is common?
I asked about cleaning or blockage but was told that its always been like this.
Any ideas or truth to this?

[TownsendsFJR1300]

I'm not a mechanic but I have three F225s. I don't think the weak TT is anything to worry about. If you are not getting any alarms or overheats you are good to go. One thing you write is unusual, that the TT you view isn't getting any stronger at higher RPMs. Did anyone recently replace the impeller?

I'd invest in the Yamaha YDS and check the engine for codes (normal or irregular) and Volts output of the charging system, and water temperatures of the block while running 10 minutes or more.

Hedland said "when motoring along but at idle became VERY hot coming out".. but... if you want to know HOW "hot" just run the YDS. YDS will tell you exactly what the temps are in your block from minute to minute... at idle up to 5000 RPMs. Temp of 248 on the YDS will trigger an overheat alarm.... (248) degrees is in parenthesis on the YDS indicating a high/danger temperature limit.

How hot is yours getting?

I didn't have one problem with any of my F225s for the first 5 years and 450 hours of operation. The YDS will tell you a lot about the engine. Stuff you really want to know!

Good luck.

Changing an impeller after 80 hours is "nuts", if you ask me. Why they do that?

The hours re the water pump doesn't matter as much as the AGE of the impeller. If its old and hasn't been used much, it will take a "set" and the vanes will NOT expand (the rubber has hardened) and pump as much as it should...

Re the temps, I don't buy its designed to run hotter nowadays.. If your running in saltwater, the higher temps in the engine are cooking to cook that salt in your block and cause premature "caking" of salt build up in the water passages.

IMHO, I'd at least pull the thermostats, check for salt build up and test them (if they look good) per the Yamaha manual hanging them in a pot inwater on the stove. You should see them open and close....

Re the TT stream, my F150 is slightly weaker at idle (just had a "Master tech", the higest rating((not the right name)) replace it and the two seals below the SS plate(one which did fail) on the drive shaft. The stream does get stronger as you raise the RPM's off idle, so I don't buy that either...

I would have a Yamaha tech inspect it (well worth the $ in your case). It could be as simple as a water pump, thermostat or as bad as major salt build up in the coolant passages (a $700 fix)

If you have a lazer thermo gun, (or borrow one), I'd take some temps as various parts of the coolant system while at temp, it may show some clues(ie, one area is considerably hotter than another on the other bank).

Please post your results..